If the user selects - current view - in the export dialog, the export button is working and the user is asked for the export location.
But if the users selects - Aufgaben - the export button is not working. There is no question about the export location. It seems that in this case the button is without function.
Also the export to an ics file is not working properly. It includes only the following lines:
PRODID:-Roundcube libcalendaring 1.1.5SabreSabre VObject 2.1.3EN